Hello Hamza,
When it comes to online education, I personally love the Udemy platform. I've been using it for many years and have enrolled in some really fantastic marketing courses. There are a lot to choose from and every few months all of the courses site-wide go on sale for approximately $10 - $20 USD. Plus, it's international, has lifetime access and a 30 day return policy.
Course creators are independent contractors and range from individual people to professional companies. Some of the "marketing bootcamp" style courses on Udemy are 10+ hours long! Marketing is such a huge topic, so it might be best to start with one of the generalized "bootcamp" type master classes, and from there decide on your niche and study further.
Phoenix Knor'malle
Brand Ambassador at https://www.mysticsense.com/